Antenna temperature

From Glossary of Meteorology

antenna temperature

An equivalent blackbody temperature that characterizes the noise power at the terminals of an antenna.

Specifically, the antenna temperature is the temperature of a blackbody radiator that, when placed around an idealized loss-free antenna, produces the same noise power as that of the actual antenna. Antenna temperature may also refer to the noise temperature of the antenna as determined by not only the coupling of the antenna to environmental noise sources, but also noise generated by resistive losses within the antenna.